1. Field of the Invention
The present invention relates to an electronic controlled drive apparatus, and more particularly to an electronic controlled drive apparatus which is mounted on a moving vehicle such as a boat, to conduct drive control of an internal combustion engine provided in the moving vehicle.
2. Description of the Related Art
In a marine field, there has been generally used a boat that is provided with an outboard engine in the rear of the boat, and which moves forward or backward according to the rotational direction of a propeller provided below the outboard engine. When such a boat in a forward running state is suddenly stopped in case of an emergency while driving the boat, or in the case where the boat is brought alongside the pier, a boat driver has conducted a switching operation in the order of xe2x80x9cforward (F: advance)xe2x80x9d, xe2x80x9cneutral (N)xe2x80x9d, and xe2x80x9creverse (R: backward)xe2x80x9d using a shift lever to stop the boat because the boat is not provided with a brake (for example, see JP 3278949 B).
However, there are the following problems with respect to such a conventional method. When a forward speed is high, even if the operation mode is switched to the xe2x80x9cneutralxe2x80x9d by the shift lever to cut drive power to the propeller, the boat continues to run forward for some time and the propeller continues to rotate slowly forward according to a flow due to the forward running of the boat. Therefore, in order to immediately stop the boat in this state, when the operation mode is switched to the xe2x80x9creversexe2x80x9d mode by the shift lever to reverse the rotational direction of the propeller, an extremely large load is applied to the engine, thereby temporarily and suddenly reducing the number of revolutions of the engine. Thus, in particular, an engine having small torque in a low rotation region causes engine stalling, and therefore the boat cannot be adequately stopped.
The present invention has been made to solve the above-mentioned problem. Therefore, an object of the present invention is to obtain an electronic controlled drive apparatus capable of reducing a load applied to an engine by conducting shift connection after a rotation speed of the drive axis of a propeller is sufficiently reduced upon a rapid shift reverse operation to thereby prevent a defect such as engine stalling.
According to the present invention, there is provided an electronic controlled drive apparatus that conducts drive control of an internal combustion engine which is provided in a moving vehicle, the electronic controlled drive apparatus including: control means having an operational lever. The electronic controlled drive apparatus also includes target value calculating means for calculating a target throttle opening degree and a target shift position based on an inputted position of the operational lever. Further, the electronic controlled drive apparatus includes a throttle actuator that opens or closes a throttle of the internal combustion engine in accordance with the target throttle opening degree by an operation of the control means. In addition, the electronic controlled drive apparatus includes a shift actuator that actuates a shift in accordance with the target shift position by an operation of the control means. The electronic controlled drive apparatus also includes engine rotation number holding means for obtaining an engine rotation number when the target shift position is released and holding the obtained engine rotation number. The electronic controlled drive apparatus further includes waiting time calculating means for calculating a shift drive waiting time in accordance with the held engine rotation number. In the electronic controlled drive apparatus, the control means starts counting of the shift drive waiting time when the target shift position is released, and allows the shift actuator to be driven after a lapse of the shift drive waiting time. Thereby, the load applied to the engine can be reduced to prevent a defect such as engine stalling by conducting shift connection after the rotation speed of the drive axis of the propeller is sufficiently reduced upon the rapid shift reverse operation.